using System;class SumOf1divideK{    static void Main()    {        double sum = 1.0f;        for (double i = 2; 1 / i >= 0.001; i++)        {            if (i % 2 == 0)            {                sum = sum + 1 / i;            }            else            {                sum = sum - 1 / i;            }        }        Console.WriteLine("{0:0.000}", sum);      }}